You haven't by chance verified that the $1.70 cable fits well in the Captivate slot?
I only ask because I have a mini-to-micro USB adapter I'm using with a mini USB cable right now and it appears to fit in fine. Unfortunately in reality the plastic around the male piece blocks it from slotting in fully and I have to fiddle with it to ensure it's in well enough to charge. Moving the phone in the slightest can dislodge it and sever the connection.
I'd like to buy this cable to work with my current home/car USB chargers but wanted to make sure it wouldn't have the same issue.
I can't post a URL yet so replace x's with t's to see my illustration: hxxp://imgur.com/TCi5h.jpg